Without warning, Princess Luna had turned into Nightmare Moon and now threatens to plunge the world into eternal night. But didn't the elements of harmony cleansed Nightmare Moon from Luna? What is the true relationship between Luna and Nightmare Moon? Are they the same pony or two completely different entities?
The elements of harmony had been used over the centuries as a means of destroying chaos but is there another side to the elements of harmony and what exactly did it do to Luna?